DC power melting lighting wires

[Jeep4o]

Good Afternoon -
first time poster...please be gentle...ha.

I purchased a 2007 Rockwood Premier 2514G last week from another owner and have been doing some maintenance on it. The first night I had it, I used the DC overhead lights and they began to dim when I'd turn on more than one...converter (WFCO WF-8725-P) would kick in as well when more than one was turned on....then they flickered and I could smell something melting. The lighting wiring connection at the ceiling had melted at the connectors...lights stopped working at that point.

I am not an electrical expert or a camper expert so I'm just getting up to speed with how this whole thing functions...I think I get the basics as of now....I am an engineer, but not that kind!

I checked and then replaced the main 7 year old 12v battery which I was told by a battery shop was bad....I then checked all the fuses and brushed off the connections at the battery. I reconnected the melted connections and tried the lighting again...the lighting works again but I could tell the connection was getting too hot and the lights were dimming and converter coming on when I turned more than one overhead DC light on.

the overhead fan, water pump and radio work fine.

After researching further I'm reading things like it could be:
1) the old incandescent bulbs...one or more might be bad?
2) something to do with the grounding of the system...I'm not sure if the lighting is grounded separately from the other DC items? or where to find it.
3) Bad converter...but why is everything else working? I thought power for the DC when plugged in, still came from the 12v battery? or does it literally get converted at the converter and pushed out (I think the wiring overheating happens regardless of on DC or AC power).

Regardless, I'd like to switch the overhead DC lights to LED to reduce the super hot bulb and plastic temps (the covers are melted on some of them from prior owner).

I also cleaned up the auto circuit breakers (for elect lift I think) and reconnected to new battery (thick red wire to the positive, thin black in photo to positive as well). There is also a thick white wire and a thick additional black wire, both connected to the negative....from other articles and photos, that config seems to be correct.

tried to provide all the clues I had...any input or other ideas would be helpful.

Frustrated in Milwaukee,
Thank you!

[TitanMike]

Even incandescent bulbs shouldn't draw enough current to burn wires.

My guess is that the previous owner hooked something up to a lighting wire and it's drawing more power than it should. Either that or there is a short (as in pinched wire) somewhere along the lighting circuit that isn't hot until you switch on the lights.


Unless the previous owner can share whether or not they modified the wiring at all, you have a little diagnostic/search work ahead. I'd look at the wires that are burned as they travel farther from the power source (away from the battery/converter.

[Jeep4o]

Thanks @TitanMike

I'll take a look at that tonight....it does seem to be pinched (visually) as it comes out of the ceiling (from the factory)....not even a bushing or anything there to protect it, just the one wire pinched into the joint I imagine to get into the roof and get to the other lights (you can actually see it pinched in the photo I posted). I'll also check with the previous owner and see what else could have been on it...likely nothing though as there has been nothing else running when I had the lights on.

thanks for your time!

[Bama Rambler]

Do the lights seem exceptionally bright?

I would find someone to test the voltage to make sure it isn't out of range.

[Jeep4o]

BamaRambler - Not really that bright that I can tell or differentiate.

Am I checking voltage with my multi-meter at the light OR in the wires on the wall before they get to the light? (or at the converter as it's leaving?....that one I would have a difficult time figuring out without knowing which DC circuit it's on...there is no device listing for the circuits).

Odd that the wire burned before the fuse however I thought.

[Flybob]

Not sure what you mean by "The lighting wiring connection at the ceiling had melted at the connectors" Usually melting at any connection is an indication of a high resistance generating heat. Are the connectors you are referring to the Blue ones in photo 1? I do not recommend those for RV use. I would also not focus on the wiring much before the lights as a short or high resistance there would not manifest itself at the light. What bulb is installed in the light. ( number on the bulb). Most of the RV lights have a wattage limit and will not support high current bulb upgrades. I would focus on the light fixtures, bulbs and the connections to them. A photo of the light connection would help with fix ideas.

[TitanMike]

As you are going through the wiring this might also be a good time to consider upgrading to LED lights. One tenth the draw on batteries when off grid.


As an illustration on how LED lights save power, I upgraded every bulb in my house to LED's. Then I bought a Chevy Volt and installed a Level II charger in my garage.

When comparing the electrical bills on a month to month basis from before adding the LED bulbs and after upgrading as well as adding the charging for the Volt, the numbers were so close the difference was negligible.

In short I saved enough on lighting expense to pay for driving my Volt

[5picker]

All those blue Scotchloc connectors in your photo are junk.
The are the very worst way to make a connection.

Second, if the burned connection is the black thing sticking up in photo one, that could have happened because the wires were not twisted tightly and the resistance caused heat.

It looks like it should have had a wire nut that came off or somehow came up missing.

Looks like you've got some electrical wiring clean-up to do.

[Jeep4o]

Thanks for all the input, gave me some good ideas...
1) voltage checked at fixtures, good.
2) lighting wiring was pinched at ceiling...i had to pull the metal and plastic away to open it up a bit...why no grommet or edge protection from factory?!? Would have cost maybe a quarter!
3) lighting worked better but blue connection was still getting hot and lights would flicker when i rolled it in my hand...i then cut those cheap blue connections out as recommended here...and replaced w butt connections, crimped and taped. Prob should have heat shrunk but i can always go back and redo if needed.

So it was a combo of both items...cheap wiring job (pinched) and cheap connectors that were probably installed that way from factory.

I’d like to switch all current (RG921)$ bulbs as well to save on po.
Thanks to All who commented and offered input! Much appreciated!

[Bama Rambler]

Thanks for the detailed write-up of what you found and how you fixed it.
It's always good to know the solution. It helps us help someone in the future.

[FORKLIFMAN]

For someone that doesn't, know much about electrical. looks like a pro repair! When I was working, we called the Blue Scotch locks you removed, Job Security!

[Flybob]

Glad you got it working. It is unlikely that the pinched wires caused this issue, but rather the blue splices. It is good however that you fixed the pinched wiring as that would have eventually caused a short and blown the fuse. You should be much better off now. For future electrical work, I suggest soldering connections and using heat shrink tubing just because of the environment that RVs encounter.

[Larry-NC]

Originally Posted by Jeep4o

Good Afternoon -
first time poster...please be gentle...ha.

I purchased a 2007 Rockwood Premier 2514G last week from another owner and have been doing some maintenance on it. The first night I had it, I used the DC overhead lights and they began to dim when I'd turn on more than one...converter (WFCO WF-8725-P) would kick in as well when more than one was turned on....then they flickered and I could smell something melting. The lighting wiring connection at the ceiling had melted at the connectors...lights stopped working at that point.

I am not an electrical expert or a camper expert so I'm just getting up to speed with how this whole thing functions...I think I get the basics as of now....I am an engineer, but not that kind!

I checked and then replaced the main 7 year old 12v battery which I was told by a battery shop was bad....I then checked all the fuses and brushed off the connections at the battery. I reconnected the melted connections and tried the lighting again...the lighting works again but I could tell the connection was getting too hot and the lights were dimming and converter coming on when I turned more than one overhead DC light on.

the overhead fan, water pump and radio work fine.

After researching further I'm reading things like it could be:
1) the old incandescent bulbs...one or more might be bad?
2) something to do with the grounding of the system...I'm not sure if the lighting is grounded separately from the other DC items? or where to find it.
3) Bad converter...but why is everything else working? I thought power for the DC when plugged in, still came from the 12v battery? or does it literally get converted at the converter and pushed out (I think the wiring overheating happens regardless of on DC or AC power).

Regardless, I'd like to switch the overhead DC lights to LED to reduce the super hot bulb and plastic temps (the covers are melted on some of them from prior owner).

I also cleaned up the auto circuit breakers (for elect lift I think) and reconnected to new battery (thick red wire to the positive, thin black in photo to positive as well). There is also a thick white wire and a thick additional black wire, both connected to the negative....from other articles and photos, that config seems to be correct.

tried to provide all the clues I had...any input or other ideas would be helpful.

Frustrated in Milwaukee,
Thank you!

Type 1141 and type 1156 lamps look identical. Trailers are fitted and designed for 1141 lamps. Owners who don't know any better can go into Walmart or the auto parts store and pick lamps that "look just like mine."

But the 1141 consumes 18.4 watts and the 1156 consumes 26.9--50% more. First thing to do is check the lamps.

Second thing to do is replace them with LEDs that consume only 2-3 watts. Just look for LEDs with a BA15S base.

[PenJoe]

It is often difficult to second guess, when not there to physically assess the damage and determining where the wires are originating/terminating. Can you advise at what point the wire insulation is melted? A wiring short can not only melt the insulation, it can also damage the wire like an arc welder.

Burned wires are generally an indication of a deal short. It is hard to distinguish by the pictures, but the insulation may have melted and the positive wire is shorting with the negative when the switch is on. If the wires are coming through aluminum, the positive wire insulation may have been damaged also, initially causing the short. Now that the lights no longer work, the fuse has probably blown.

First, try to make the opening larger. Is there enough slack to do a wire splice? Can it be determined where the damaged wires originated? If it is from another fixture, it may be possible to attach new wires to the old and pull them through. By first pulling from one end and then the other, you can determine if the wires will slide freely. You will only have one chance to do it right. If you are going to try this, I would attach a string or heavy fishing line ahead of the wire to wire attachments so that the wire can be pulled back if necessary. Or, if too tight, pull the line through first. Though I have held my breath many times doing this, so far, it has worked for me.

Your second picture shows some pretty rusty terminal bolts. That should not be a part of the lights shorting. However, it would be suggested to replace that fuse link. You could try cleaning up what is there using a rust neutralizer such as Ospho. Rust neutralizers will also prevent future rust on bare metal.

Depending on where the wires are and how difficult it would be to internally fish new wires, there are wire chase channels that are an effect way to route wires. Keep us abreast.

https://www.amazon.com/One-Cord-Chan...7NGYTQ2XB2RKRG

[5picker]

Glad you got your issues resolved.
And thanks for sticking with the thread and coming back to report your progress.
Many folks don't do that and it's a shame.
All these threads can be helpful to someone at some point but without knowing the outcome, they fall short.
Kudos to you!

[Jeep4o]

Originally Posted by Flybob

Glad you got it working. It is unlikely that the pinched wires caused this issue, but rather the blue splices. It is good however that you fixed the pinched wiring as that would have eventually caused a short and blown the fuse. You should be much better off now. For future electrical work, I suggest soldering connections and using heat shrink tubing just because of the environment that RVs encounter.

I agree, should have soldered and heat shrunk it...I replaced a light on the outside tonight and did that exact process...very neat and waterproof as well, hopefully won't pull apart as well. Appreciate the input...continuing to learn how this thing functions and how to maintain it.

[TowPro]

if you buy LED's you want to look for 2 things.


Voltage. some just say 12V, that is not good enough since your camper might see 11-15.5 or so. it should be listed something like 10-20V. its the high number you are are looking for. 18V might be OK but as the voltage goes up over 12, the heat output from light increases. My first LED's were just marked 12v and 1/2 of them burned up in first month.



Color or Kalvin. I would recommend warm white, 2700K-3000K. as the number gets higher they become more white, into blue scale. warm white is close to a incandescent light. to me Bright white is un-natural and has glare, and those blue ones discolor everything.


amazon is full of them.

[Bama Rambler]

I agree that you need to look for LED's that are rated for at least 15 volts.

I'm partial to the more daylight color temps. Something in the 4000º Kelvin range. Much above that and you're getting into the blue spectrum.